MATHEMATICS (MEI) 4755 Further Concepts for Advanced Mathematics (FP1)

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1 ADVANCED SUBSIDIARY GCE MATHEMATICS (MEI) 4755 Further Concepts for Advanced Mathematics (FP1) QUESTION PAPER Candidates answer on the printed answer book. OCR supplied materials: Printed answer book 4755 MEI Examination Formulae and Tables (MF2) Other materials required: Scientific or graphical calculator Friday 20 May 2011 Afternoon Duration: 1 hour 30 minutes INSTRUCTIONS TO CANDIDATES These instructions are the same on the printed answer book and the question paper. The question paper will be found in the centre of the printed answer book. Write your name, centre number and candidate number in the spaces provided on the printed answer book. Please write clearly and in capital letters. Write your answer to each question in the space provided in the printed answer book. Additional paper may be used if necessary but you must clearly show your candidate number, centre number and question number(s). Use black ink. Pencil may be used for graphs and diagrams only. Read each question carefully. Make sure you know what you have to do before starting your answer. Answer all the questions. Do not write in the bar codes. You are permitted to use a scientific or graphical calculator in this paper. Final answers should be given to a degree of accuracy appropriate to the context. INFORMATION FOR CANDIDATES This information is the same on the printed answer book and the question paper. The number of marks is given in brackets [ ] at the end of each question or part question on the question paper. You are advised that an answer may receive no marks unless you show sufficient detail of the working to indicate that a correct method is being used. The total number of marks for this paper is 72. The printed answer book consists of 16 pages. The question paper consists of 4 pages. Any blank pages are indicated. INSTRUCTION TO EXAMS OFFICER / INVIGILATOR Do not send this question paper for marking; it should be retained in the centre or destroyed. OCR 2011 [D/102/2663] OCR is an exempt Charity RP 0I23 Turn over

2 2 Section A (36 marks) 1 (i) Write down the matrix for a rotation of 90 anticlockwise about the origin. [1] (ii) Write down the matrix for a reflection in the line y = x. [1] (iii) Find the matrix for the composite transformation of rotation of 90 anticlockwise about the origin, followed by a reflection in the line y = x. [2] (iv) What single transformation is equivalent to this composite transformation? [1] 2 You are given that = 3 2j and w = 4 + j. (i) Express + w w in the form a + bj. [3] (ii) Express w in modulus-argument form. [3] (iii) Show w on an Argand diagram, indicating its modulus and argument. [2] 3 The equation x 3 + px 2 + qx + 3 = 0 has roots α, β and γ, where α + β + γ = 4 α 2 + β 2 + γ 2 = 6. Find p and q. [5] 4 Solve the inequality 5x x < x. [6] Given that (3r 1)(3r + 2) 1 3r 1 1 3r + 2, find 1, giving your answer as an (3r 1)(3r + 2) r=1 exact fraction. [5] 6 Prove by induction that n 3 = 1 4 n2 (n + 1) 2. [7] OCR Jun11

3 3 Section B (36 marks) 7 A curve has equation y = (x + 9)(3x 8). x 2 4 (i) Write down the coordinates of the points where the curve crosses the axes. [3] (ii) Write down the equations of the three asymptotes. [3] (iii) Determine whether the curve approaches the horizontal asymptote from above or below for (A) large positive values of x, (B) large negative values of x. [3] (iv) Sketch the curve. [3] 8 A polynomial P() has real coefficients. Two of the roots of P() = 0 are 2 j and 1 + 2j. (i) Explain why P() cannot be a cubic. [1] You are given that P() is a quartic. (ii) Write down the other roots of P() = 0 and hence find P() in the form 4 + a 3 + b 2 + c + d. [8] (iii) Show the roots of P() = 0 on an Argand diagram and give, in terms of, the equation of the circle they lie on. [2] 9 The simultaneous equations 2x y = 1 3x + ky = b are represented by the matrix equation M( x y ) = ( 1 b ). (i) Write down the matrix M. [2] (ii) State the value of k for which M 1 does not exist and find M 1 in terms of k when M 1 exists. Use M 1 to solve the simultaneous equations when k = 5 and b = 21. [7] (iii) What can you say about the solutions of the equations when k = 3 2? [1] (iv) The two equations can be interpreted as representing two lines in the x-y plane. Describe the relationship between these two lines (A) when k = 5 and b = 21, (B) when k = 3 and b = 1, 2 (C) when k = 3 2 and b = 3 2. [3] OCR Jun11

4 4 THERE ARE NO QUESTIONS PRINTED ON THIS PAGE Copyright Information OCR is committed to seeking permission to reproduce all third-party content that it uses in its assessment materials. OCR has attempted to identify and contact all copyright holders whose work is used in this paper. To avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced in the OCR Copyright Acknowledgements Booklet. This is produced for each series of examinations and is freely available to download from our public website ( after the live examination series. If OCR has unwittingly failed to correctly acknowledge or clear any third-party content in this assessment material, OCR will be happy to correct its mistake at the earliest possible opportunity. For queries or further information please contact the Copyright Team, First Floor, 9 Hills Road, Cambridge CB2 1GE. OCR is part of the Cambridge Assessment Group; Cambridge Assessment is the brand name of University of Cambridge Local Examinations Syndicate (UCLES), which is itself a department of the University of Cambridge. OCR Jun11

5 ADVANCED SUBSIDIARY GCE MATHEMATICS (MEI) 4755 Further Concepts for Advanced Mathematics (FP1) PRINTED ANSWER BOOK Candidates answer on this printed answer book. OCR supplied materials: Question paper 4755 (inserted) MEI Examination Formulae and Tables (MF2) Other materials required: Scientific or graphical calculator Friday 20 May 2011 Afternoon Duration: 1 hour 30 minutes * * * * Candidate forename Candidate surname Centre number Candidate number INSTRUCTIONS TO CANDIDATES These instructions are the same on the printed answer book and the question paper. The question paper will be found in the centre of the printed answer book. Write your name, centre number and candidate number in the spaces provided on the printed answer book. Please write clearly and in capital letters. Write your answer to each question in the space provided in the printed answer book. Additional paper may be used if necessary but you must clearly show your candidate number, centre number and question number(s). Use black ink. Pencil may be used for graphs and diagrams only. Read each question carefully. Make sure you know what you have to do before starting your answer. Answer all the questions. Do not write in the bar codes. You are permitted to use a scientific or graphical calculator in this paper. Final answers should be given to a degree of accuracy appropriate to the context. INFORMATION FOR CANDIDATES This information is the same on the printed answer book and the question paper. The number of marks is given in brackets [ ] at the end of each question or part question on the question paper. You are advised that an answer may receive no marks unless you show sufficient detail of the working to indicate that a correct method is being used. The total number of marks for this paper is 72. The printed answer book consists of 16 pages. The question paper consists of 4 pages. Any blank pages are indicated. OCR 2011 [D/102/2663] OCR is an exempt Charity RP 0I23 Turn over

6 2 Section A (36 marks) 1 (i) 1 (ii) 1 (iii) 1 (iv) OCR 2011

7 3 2 (i) 2 (ii) 2 (iii) OCR 2011 Turn over

8 4 3 OCR 2011

9 5 4 OCR 2011 Turn over

10 6 5 OCR 2011

11 7 5 (continued) OCR 2011 Turn over

12 8 6 OCR 2011

13 9 6 (continued) OCR 2011 Turn over

14 10 Section B (36 marks) 7 (i) 7 (ii) 7 (iii) OCR 2011

15 11 7 (iv) OCR 2011 Turn over

16 12 8 (i) 8 (ii) OCR 2011

17 13 8 (ii) (continued) OCR 2011 Turn over

18 14 8 (iii) OCR 2011

19 15 9 (i) 9 (ii) OCR 2011 Turn over

20 16 9 (iii) 9 (iv) Copyright Information OCR is committed to seeking permission to reproduce all third-party content that it uses in its assessment materials. OCR has attempted to identify and contact all copyright holders whose work is used in this paper. To avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced in the OCR Copyright Acknowledgements Booklet. This is produced for each series of examinations and is freely available to download from our public website ( after the live examination series. If OCR has unwittingly failed to correctly acknowledge or clear any third-party content in this assessment material, OCR will be happy to correct its mistake at the earliest possible opportunity. For queries or further information please contact the Copyright Team, First Floor, 9 Hills Road, Cambridge CB2 1GE. OCR is part of the Cambridge Assessment Group; Cambridge Assessment is the brand name of University of Cambridge Local Examinations Syndicate (UCLES), which is itself a department of the University of Cambridge. OCR 2011

21 GCE Mathematics (MEI) Advanced Subsidiary GCE Unit 4755: Further Concepts for Advanced Mathematics Mark Scheme for June 2011 Oxford Cambridge and RSA Examinations

22 OCR (Oxford Cambridge and RSA) is a leading UK awarding body, providing a wide range of qualifications to meet the needs of pupils of all ages and abilities. OCR qualifications include AS/A Levels, Diplomas, GCSEs, OCR Nationals, Functional Skills, Key Skills, Entry Level qualifications, NVQs and vocational qualifications in areas such as IT, business, languages, teaching/training, administration and secretarial skills. It is also responsible for developing new specifications to meet national requirements and the needs of students and teachers. OCR is a not-for-profit organisation; any surplus made is invested back into the establishment to help towards the development of qualifications and support which keep pace with the changing needs of today s society. This mark scheme is published as an aid to teachers and students, to indicate the requirements of the examination. It shows the basis on which marks were awarded by Examiners. It does not indicate the details of the discussions which took place at an Examiners meeting before marking commenced. All Examiners are instructed that alternative correct answers and unexpected approaches in candidates scripts must be given marks that fairly reflect the relevant knowledge and skills demonstrated. Mark schemes should be read in conjunction with the published question papers and the Report on the Examination. OCR will not enter into any discussion or correspondence in connection with this mark scheme. OCR 2011 Any enquiries about publications should be addressed to: OCR Publications PO Box 5050 Annesley NOTTINGHAM NG15 0DL Telephone: Facsimile: publications@ocr.org.uk

23 4755 Mark Scheme June 2011 Qu Answer Mark Comment Section A 1(i) Accept expressions in sin and cos 1(ii) (iii) M A1ft Ans (ii) x Ans (i) attempt evaluation 1(iv) Reflection in the x axis 2(i) zw 1 j 4 j w 4 j 4 j M1 [5] Multiply top and bottom by -4 - j 3 5j 3 5 j A1 A1 [3] Denominator = 17 Correct numerators 2(ii) w 17 2(iii) 1 arg w arctan w 17 cos2.90 jsin 2.90 [3] Not degrees c.a.o. Accept 17, 2.90 Accept 166 degrees Correct position Mod w and Arg w correctly shown [2] 3 4 p p q q 5 M1 A1 M1 A1 A1 [5] May be implied Attempt to use 2 o.e. Correct c.a.o. 1

24 4755 Mark Scheme June x x 2 x 4 3 5x x 4x 3 0 x x x 0 x x1 1 M1* A1 A1 Method attempted towards factorisation to find critical values x = 0 x = 1, x = -1 x 1, 1 x0 M1dep* Valid method leading to required intervals, graphical or algebraic A1 A1 [6] x 1 1 x 0 SC B2 No valid working seen x 1 1 x r1 r r r1 r r M1 A1 A1 M1 A1 [5] Attempt to use identity may be implied Correct use of 1/3 seen Terms in full (at least first and last) Attempt at cancelling c.a.o. 2

25 4755 Mark Scheme June When n = 1, n n1 2 1, 4 so true for n = 1 Assume true for n = k k r k k 1 r1 4 k r k k 1 k 1 r k 1 [ k 4 k 1] k 1 [ k 4k 4] k 1 k k 1 k But this is the given result with k + 1 replacing k. Therefore if it is true for k it is true for k + 1. Since it is true for n = 1, it is true for n = 1, 2, 3 and so true for all positive integers. E1 M1 M1 A1 E1 E1 [7] Assume true for k Add k 1 th Factor of k term to both sides c.a.o. with correct simplification Dependent on A1 and previous E1 Dependent on and previous E1 and correct presentation Section A Total: 36 3

26 4755 Mark Scheme June 2011 Section B 7(i) 7(ii) 7(iii) 0, , 0,, 0 3 x 2, x 2 and y 3 Large positive x, y 3 from above Large negative x, y 3 from below [3] [3] (e.g. consider x 100, or convincing algebraic argument) M1 [3] Must show evidence of working 7(iv) - [3] 3 branches correct Asymptotes correct and labelled Intercepts correct and labelled 4

27 4755 Mark Scheme June (i) 8(ii) Because a cubic can only have a maximum of two complex roots, which must form a conjugate pair. E1 [1]. 2 j, 1 2j P( z) z 2 j z 2 j z 1 2j z 1 2j z z z 4z 5z 2z z z z z M1 M1 A4 Use of factor theorem Attempt to multiply out factors -1 for each incorrect coefficient OR 2a 2 2b 2 10 c d P( z) z 2z 2z 10z25 M2 A3 M1 for attempt to use all 4 root relationships. M2 for all correct a = -2 b, c, d correct -1 for each incorrect 8(iii) [8] -1 for P(z) not explicit, following A4 or A3 All correct with annotation on axes or labels z 5 [2] 5

28 4755 Mark Scheme June 2011 Qu Answer Mark Comment Section B (continued) 9(i) 2 1 B2-1 each error M [2] 3 k 9(ii) 1 M does not exist for 2k 3 0 M1 May be implied k k 1 M 2k A1 Correct inverse M1 A1ft A1 Attempt to pre-multiply by their inverse Correct matrix multiplication c.a.o. x 2, y 3 A1ft At least one correct [7] 9(iii) There are no unique solutions [1] 9(iv) (A) Lines intersect (B) Lines parallel (C) Lines coincident [3] Section B Total: 36 Total: 72 6

29 OCR (Oxford Cambridge and RSA Examinations) 1 Hills Road Cambridge C 2EU OCR Customer Contact Centre Qualifications (General) Telephone: Facsimile: general.qualifications@ocr.org.uk For staff training purposes and as part of our quality assurance programme your call may be recorded or monitored Oxford Cambridge and RSA Examinations is a Company Limited by Guarantee Registered in England Registered Office; 1 Hills Road, Cambridge, C 2EU Registered Company Number: OCR is an exempt Charity OCR (Oxford Cambridge and RSA Examinations) Head office Telephone: Facsimile: OCR 2011

30 Examiners Reports June : Further Concepts for Advanced Mathematics General Comments There were many scripts showing good understanding and ability. The majority of candidates were well prepared, and most had sufficient time to cover all the questions. There were some surprising lapses in elementary algebraic work, not confined to the lower-scoring candidates. On the whole solutions were clearly written, if not always fully logical. Diagrams were sometimes difficult to decipher. After scanning, alterations can make the intention obscure. Pencil for diagrams is really essential, together with a quality eraser, in case of mistakes. Comments on Individual Questions 1 Generally this question was well done. (i) (ii) (iii) (iv) A surprising number of candidates did not obtain the correct matrix for this rotation. Several candidates had learned the general form for a rotation, and wrote it in terms of sin 90 and cos 90, unsimplified, but usually correct. Some errors in signs occurred. This was usually correctly answered, but there were instances when the identity matrix was given, which should have rung alarm bells in part (iii). Follow through marking here allowed some recovery from earlier errors, but there were many instances of matrices written in the wrong order. It was not essential to answer this from the result of (iii), and possible to check the previous result by thinking through the transformations. Some candidates thought that the description was achieved by writing down the matrix again. 2 This question was also well answered by many. (i) (ii) (iii) A good response. Nearly all candidates knew how to use the complex conjugate, but some obtained 15 instead of 17 in the denominator. The modulus of w was usually correct, but the argument was often found from arctan 0.25 or arctan(-0.25) without adjustment. Several candidates gave their argument in degrees, and some rounded it inappropriately. Not all candidates wrote down the required form for w after finding these components. The mark for placing w at (-4, 1) was often the only one scored here, and sometimes this was lost through the lack of adequate annotation. It was not uncommon for the argument to be wrongly shown, and sometimes two angles were indicated, with the choice left for the examiner. A few diagrams showed the locus arg(z w) = arg w, and had nothing available with which to indicate the modulus. 17

31 Examiners Reports June Almost all scored two marks for p, although some gave the wrong sign. Most candidates attempted (α+β+γ) 2 in order to find q, but often with errors. A few candidates assumed that the roots were 1, 1 and 2, which satisfied the two equations given but did not fit with the constant term in the cubic. 4 This question was not well answered, except by a very few. Most candidates chose to 5x try to solve the equation x, but errors were frequent, for example x 3 + 4x + 5x 2 ( x 4) or x 3 + 4x 5 instead of x 3 + 4x 5x. The critical value of x = 0 was often lost because of division by x. It was also common to see x factorised to (x - 2)(x + 2) and asymptotes drawn when a sketch was attempted. Even when the correct critical values were found, many candidates could not follow a coherent method to obtain the intervals required. 5 This question was well answered. The main mistake was to forget to multiply by 1/3. Some multiplied by 3. Some candidates gave the sum of n terms without substituting n = 20. A small minority summed twenty fractions with their calculators which did not demonstrate familiarity with the specification. A smaller minority thought that the standard results for r and r 2 could be used in the denominator. 6 Many good, carefully worded answers were seen. It is a shame when otherwise good k k 3 work is spoiled by lack of attention to details, for example n or k 3, or even the statement that k k ( k 1). There are still candidates who do not use the formal 4 if then statement in the concluding stages of the argument, and also those who do not appreciate that answering the question requires rather more than a sketchy indication of working Candidates who could not factorise the expression k ( k 1) ( k 1) and multiplied 4 out gained credit if they also showed that this matched the expansion of the target expression, but some candidates lost marks by failing to show how the quartic they obtained then factorised to the target, quoting the result without working. 7 Overall this question was well done. r 1 r 1 (i) (ii) (iii) (iv) When asked for co-ordinates, some candidates cannot bring themselves to write down pairs of numbers in brackets. Some candidates do not like to write down clearly three separate equations. Clear methods were usually shown, where working or a result of a calculation was needed beyond a statement of extreme values for x. Some candidates thought that positive or negative was enough to show how the curve approached y=3. Many good carefully drawn sketches showed the salient features with full annotation. However, some candidates believed that correct scales were needed, which is not necessary. Through lack of space, in many cases this led to the curves not showing clearly the approaches to the asymptotes nor the precise values of x and y where the axes were crossed and the asymptotes positioned. Some diagrams suffered from alterations which were difficult to interpret. 18

32 Examiners Reports June (i) Most candidates had the right idea but many could not express it clearly. A full explanation needed to refer to complex conjugates, more than just pairs. It was also important to make some mention of the number of roots. Although it may not have forfeited the mark, quite a lot of candidates believed that P(z), as yet unspecified, would have only four roots, rather than a minimum of four roots. (ii) (iii) Candidates who used the factors and expanded were usually more successful than those who used the root relationships. Factors with incorrect signs were seen in some scripts. In both methods, there were commonly mistakes in multiplications, for example writing (2j) 2 as 2j 2 and then obtaining -2. When the root relationships were used some candidates failed to use all six terms in αβ. Most candidates were able to show the positions of the four roots but a few gave no indication of scale. Again, alterations were sometimes confusing. Not many candidates were able to give the correct circle equation. 9 This question was well done by many but some candidates were probably running out of time. (i) (ii) Generally well answered. Most candidates gave the correct value of k, a few failed to get the right sign. Some candidates gave M -1 using k = 5 instead of in terms of k. Most candidates obtained the values of x and y through the correct method, with M -1 in the right place. A few lost marks through using another method. (iii) (iv) A number of candidates wrote no solution or can t be solved, without the other possibility. The first situation (A) was usually correctly described, but (B) and (C) were often confused. A number of answers referred to equations instead of describing lines. There were several instances of no response. 19

33 For a description of how UMS marks are calculated see: GCE Mathematics (MEI) Max Mark a b c d e u 4751/01 (C1) MEI Introduction to Advanced Mathematics Raw /01 (C2) MEI Concepts for Advanced Mathematics Raw /01 (C3) MEI Methods for Advanced Mathematics with Coursework: Written Paper Raw /02 (C3) MEI Methods for Advanced Mathematics with Coursework: Coursework Raw /82 (C3) MEI Methods for Advanced Mathematics with Coursework: Carried Forward Coursework Mark Raw (C3) MEI Methods for Advanced Mathematics with Coursework 4754/01 (C4) MEI Applications of Advanced Mathematics Raw /01 (FP1) MEI Further Concepts for Advanced Mathematics Raw /01 (FP2) MEI Further Methods for Advanced Mathematics Raw /01 (FP3) MEI Further Applications of Advanced Mathematics Raw /01 (DE) MEI Differential Equations with Coursework: Written Paper Raw /02 (DE) MEI Differential Equations with Coursework: Coursework Raw /82 (DE) MEI Differential Equations with Coursework: Carried Forward Coursework Mark Raw (DE) MEI Differential Equations with Coursework 4761/01 (M1) MEI Mechanics 1 Raw /01 (M2) MEI Mechanics 2 Raw /01 (M3) MEI Mechanics 3 Raw /01 (M4) MEI Mechanics 4 Raw /01 (S1) MEI Statistics 1 Raw /01 (S2) MEI Statistics 2 Raw /01 (S3) MEI Statistics 3 Raw /01 (S4) MEI Statistics 4 Raw /01 (D1) MEI Decision Mathematics 1 Raw /01 (D2) MEI Decision Mathematics 2 Raw /01 (DC) MEI Decision Mathematics Computation Raw /01 (NM) MEI Numerical Methods with Coursework: Written Paper Raw /02 (NM) MEI Numerical Methods with Coursework: Coursework Raw /82 (NM) MEI Numerical Methods with Coursework: Carried Forward Coursework Mark Raw (NM) MEI Numerical Methods with Coursework 4777/01 (NC) MEI Numerical Computation Raw Unit level raw mark and UMS grade boundaries June 2011 series: GCE 19